Carbureter



C. L. RAYFIELD. CRBURETER.

APPLICATION H'LEDJUNE21,1917.

l ,307,457 Patented June 24, 1919.

Maa.

m ,n @Mp CHARLES L. RAYFIELD, 0F CHICAGO, ILLINOIS.

CABBURETEB.

Specification of LettersPatent.

Patented June 24, 1919.

Application led .Tune 21, 1917. Serial No. 176,185.

To all whom 'it may concern:

Be it known that I, CHARLES L. RAYFIELD, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful. Improvements in Carbureters, of which the following is a specication.

My invention relates to thermally controlled carbureters.

One of the objects of my invention is to provide means for automatically controlling the intake of an internal combustion engine, whereby to provide suitable qualities of the fuel charges, used in starting an engine when the engine and its fuel are cold, to compensate for the results produced by such conditions.

Another and more specific object of my invention is to provide means to automatically vary the operation of a carbureter for produc-ing the fuel charges, for an internal combustion engine at time of starting when the engine is cold, by means that is responsive to the temperature of the engine which will cause suitable variations of conditions to provide proper mixture, until the desired quality of the charge has been obtained, for the normal running temperature of the engine.

Still another object of my invention is to provide means to yieldingly resist the opening of the auxiliary air valve of the carbureter, when the engine is cold, and which will reduce the resistance to the operation of said valve as the temperature of the engine rlses.

Other, further and more specific objects of my invention will become readily apparent, to persons skilled in the art, from a consideration of the following description when taken in conjunction with the drawings, wherein Figure 1 is a central vertical section of a conventional carbureter and my thermo device for varying the resistance to operation of the air admitting valve.

Fig. 2 is a fragment of a radiator of an automobile showing one means for arranging the device to be influenced by the heat of the engine.

In all the views the same reference characters are employed to indicate similar parts.

When starting an internal combustion engine its temperature is below its efficient onorative temperature. At such time theliquid fuel, such as. gasolene, is below the temperature at which it is maintained during the normal working operation of the engine. When the liquid fuel is cold it is more viscous than when it is warm, therefore, the same quantity of such fluid will not pass through a given orifice under the same pressure. It follows, then, that a smaller portion of fluid, or gasolene, passing through a fixed orifice, other conditions being unchanged, will provide an attenuated or subnormal mixture of a quality below that required for normal operation. When cold the air is heavier than when warm, that is to saw, it is specifically heavier, therefore, a given volume of air which will pass through a given orifice under a given pressure will be of greater mass thanwhen it is warmer.

It is the mass 0f air and not its volume that determines its oxygen content and it is the proportion of oxygen to hydrocarbon that determines the quality of mixture and not the volume of air per given volume of gasolene. From the above statement it will be readily deduced that with a carbureter adjusted for normal operation, there will be admitted into the cylinders of an engine a smaller quantity of gasolene and a greaterquantity of oxygen at the time when the engine is being started, thus producing a lean or subnormal attenuation of the fuel charges.

To automatically take care of the changed condition due to variations in temperature, I may use an imprisoned volatile iiuid having a critical temperature expansion, such as tetra-chlorid or carbon, ether, alcohol.l gasolene, or the like, or I may use confined air, as the transmitting medium.

In the accompanying drawings I have illustrated one embodiment of my invention for the purpose of clear disclosure, reserving, however, to myself, the right to change or vary the structure to any extent, or in any direction within the scope of the appended claims.

The casing 5 incloses the mixing chamber 6, the ioat chamber 7, and the chamber 8, within which the temperature responsive delvice 9 is contained. In the specific showing this device takes the form of a bellows diaphragm, capable of considerable relative, axial elongation and contraction. It is airtight and is connected by a pipe 10 to an airtight air chamber 11. It may be filled with air or a suitable volatile liquid or expansible SLS. g The chamber 11, to be responsive to the heat of the engine, may be submerged in the cooling Water 12, in the radiator 13, or placed therein, within the influence of the vapor arising from the water, or it may be otherwise secured to or associated with-the engine, within the influence of the heat produced thereby, whereby its content may be heated and thereby cause it to expand by the effect of the rising temperature of the engine. It is not essential to the operation of the device, therefore, that the chamber 11 bel placed actually within the radiator or influenced by the cooling water, as the desideratum is, that the rising temperature of the engine shall serve to heat the content of the device, whether the heat be applied directly or indirectly thereto. y

The air intake 14 of the carbureter is normally closed by an air valve 15. The spring 16, which moves the valve toward closed position, may be adjusted by the bearing nut 17, which Surrounds the valve stem 18, and by which the valve stem is guided. A supplemental spring 19 connects the valve 15 to the axially movable diaphragm structure This spring tends to close the valve, when the diaphragm is contracted, as shown, and in this respect it supplements the action of the valve spring 16. The valve is therefore yieldingly held closed by the combined action of the springs 16 and 19 when the expansible medium within the chamber 11, and the diaphragm structure, is below a given temperature. When the imprisoned expansible medium is heated, as by the temperature of the engine, the diaphragm structure 9 Will be expanded, thereby relaxing the spring 19, which will consequently reduce thestress with which the valve 15 is held closed, thus rendering the valve 15, more easily operable by the suction effect of the engine.

20 is the spraying nozzle of the carbureter, in communication with the liquid-containing oat chambers 7, by an opening 21. A needle valve 22 may be used to control the flow of gasolene into the nozzle. throttle.

Primaryvair passages, around the nozzle, are provided by the openings 23 of which there. may be any desired number of suitable size. i

A ioat 24 controls the quantity of liquid fuel in the oat chamber, as usual in such devices.

The operation of the device is as followsz-When the engine is cold, the air or other expansible Huid or gas within the casing 11 is cool and contracted, causing` contraction of the ,diaphragm structure 9. The decrease in volume of the confined medium, resulting from the reduction of temperature. supplemented by the external atmospheric rpressure will cause contraction of the diaphragm. This, of course, as heretofore ex- 26 is the plained, increases the tension of the spring 19. en the engine shaft is initially rotated, in the act of starting the engine, it

w1ll require greater suction to be produced by the engine to open the valve 15, to the same extent as such operation is now opposed by the combined resistance imposed by the springs 16 and 19. Consequently a mixture of suitable quality will be drawn into the cylinder, as air will beraten in largely through the primary air ports 2 i fter the engine has been operating for a while, its increased temperature will heat the cooling water which in turn will heat and expand the content of the casing 11 causing the free end of the diaphragm 9 to be moved downwardly, thereby reducing the tension of the spring 19, whereupon the air supplyyalve l5 will be more easily opened, to supply the proper proportion of air for the normal running ofthe engine. By this means compensation is made for the reduced temperature of the engine, fuel and air, at the time of starting-and during the time when the temperature of the engine is below that at which it is most eliciently operative, the charge mixture being automatically maintained against varying conditions of fuel temperature as the temperature of the engine increases.

The thermo-responsive controlling device compensates in some measure, for variation in viscosity of the liquid fuel due to changes in atmospheric temperature while the engine is running. In cold weather the engine radiates a greater quantity of heat, and while viscosity of the fuel in such weather is greater, greater resistance to the opening of the air valve 15 will be interposed by the operation of the thermo-regulator. Therefore, in this example, under the same conditions of operation of the engine, the quality of mixture will be maintained substantially constant which, otherwise, would be more attenuate in cold weather than would obtain when the weather is warmer.

In order that the rise of engine temperature may not too quickly act upon the controlling device, the chamber 11 may be placed inside of the radiator, so that the cooling water will have the effect of producing the desired results, in order that charges of uniform quality may continue to -be introduced into the engine before and after it becomes fully warmed up and otherwise capable of doing its normal work.

Having described my invention, what- I v air operable to be opened by the suction of valve spring tending to hold the valve closed.

when the temperature of the engine is below that acquired during normal operation and adapted to relax said supplementary spring when the temperature of the engine rises. v

3. A earbureter having an intake valve; yielding means to normally hold said valve closed; mechanically-operable means for supplementing the valve closing means and means extending from said mechanically operable means to said engine to move the former, thereby to reduce opposition to movement of said valve upon rise of temperature of the engine.

4. A carburetor having an intake valve; yielding means to normally hold said valve closed; mechanicallyoperable means for supplementing the valve closing means; and a conduit,` containing an expansible medium, extending from said niechanically-operal'ile means to said engine to move said mechanically-operable means whereby to decrease resistance to movementI of said valve when the temperature of the engine is increased by its opera-tion.

5. A carbureter having an intake valve; yielding means to normally hold the valve closed; an expansible casing to supplement the valve closing means, another casing subject to the heat of the engine, and a closedv conduit connected to said casing, said easing and eondult hermetleally closed and contammg an expansible fluld to vary the resistance to movementl of said valve by variation of temperature of said engine.

6. A carbureter having an intake valve and a fuel valve in combination With a movable temperature-responsive device; a easing, containing an expansible medium, for

inclusion within the radiator of an engine;.

a conduit connecting said casing to said Jfemperature-responsive device, said device, casing and conduit hermetically sealed, and means, operable by the latter to resist opening of one of said valves, responsive to the temperature of the cooling water of the engine.

7. A earburetcr having an auxiliary air inlet and a valve therefor, primary means for normally holding said valve closed against suction of the engine, secondary means for assisting said primary means in holding the valve closed, a temperature responsive device subject to the heat of the enginev connected to Said secondary means for controlling the same.

S. A carburetor including an auxiliary air inlet and a valve therefor normally opened by the suction of the engine, primary means comprising a spring for holding the valve closed against the suction of the. engine, secondary means comprising an additional spring assisting said primary means in holding the valve closed, a temperature responsive device subject to the heat of the engine connected t0 said additional spring to regulate the tension thereof. whereby as the heat of the engine increases the resistance to the opening of the valve by the suction of the engine will be decreased.

In testimony whereof I hereunto set my hand.

CHARLES L. RAYFIELD. 

